Index: Riskeer/Revetment/src/Riskeer.Revetment.IO/Configurations/WaveConditionsCalculationConfigurationImporter.cs
===================================================================
diff -u -r16a668f8e7d77ae95f3f11fa1f73dc9e081e8444 -re5ae21624afdf7f1608f245f7719f9fe216a1bf2
--- Riskeer/Revetment/src/Riskeer.Revetment.IO/Configurations/WaveConditionsCalculationConfigurationImporter.cs	(.../WaveConditionsCalculationConfigurationImporter.cs)	(revision 16a668f8e7d77ae95f3f11fa1f73dc9e081e8444)
+++ Riskeer/Revetment/src/Riskeer.Revetment.IO/Configurations/WaveConditionsCalculationConfigurationImporter.cs	(.../WaveConditionsCalculationConfigurationImporter.cs)	(revision e5ae21624afdf7f1608f245f7719f9fe216a1bf2)
@@ -314,22 +314,24 @@
         private bool TrySetStepSize(WaveConditionsCalculationConfiguration calculationConfiguration,
                                     ICalculation<WaveConditionsInput> calculation)
         {
-            RoundedDouble stepSize = calculationConfiguration.StepSize.HasValue
-                                         ? (RoundedDouble) calculationConfiguration.StepSize.Value
-                                         : RoundedDouble.NaN;
-            try
+            if (calculationConfiguration.StepSize.HasValue)
             {
-                calculation.InputParameters.StepSize = stepSize;
+                double stepSize = calculationConfiguration.StepSize.Value;
+
+                try
+                {
+                    calculation.InputParameters.StepSize = (RoundedDouble) stepSize;
+                }
+                catch (ArgumentOutOfRangeException e)
+                {
+                    Log.LogOutOfRangeException(string.Format(
+                                                   RiskeerCommonIOResources.TryReadParameter_Value_0_ParameterName_1_is_invalid,
+                                                   stepSize,
+                                                   "stapgrootte"),
+                                               calculation.Name, e);
+                    return false;
+                }
             }
-            catch (ArgumentOutOfRangeException e)
-            {
-                Log.LogOutOfRangeException(string.Format(
-                                               RiskeerCommonIOResources.TryReadParameter_Value_0_ParameterName_1_is_invalid,
-                                               stepSize,
-                                               RiskeerCommonIOResources.CalculationConfigurationImporter_Orientation_DisplayName),
-                                           calculation.Name, e);
-                return false;
-            }
 
             return true;
         }
Index: Riskeer/Revetment/test/Riskeer.Revetment.IO.Test/Configurations/WaveConditionsCalculationConfigurationImporterTest.cs
===================================================================
diff -u -raf52022e808e96168cff588b06dfdb763d3cc486 -re5ae21624afdf7f1608f245f7719f9fe216a1bf2
--- Riskeer/Revetment/test/Riskeer.Revetment.IO.Test/Configurations/WaveConditionsCalculationConfigurationImporterTest.cs	(.../WaveConditionsCalculationConfigurationImporterTest.cs)	(revision af52022e808e96168cff588b06dfdb763d3cc486)
+++ Riskeer/Revetment/test/Riskeer.Revetment.IO.Test/Configurations/WaveConditionsCalculationConfigurationImporterTest.cs	(.../WaveConditionsCalculationConfigurationImporterTest.cs)	(revision e5ae21624afdf7f1608f245f7719f9fe216a1bf2)
@@ -125,6 +125,8 @@
                   "Een waarde van '2,2' als ondergrens van de waterstanden is ongeldig. De bovengrens van de waterstanden moet boven de ondergrens liggen.")]
         [TestCase("validConfigurationOrientationOutOfRange.xml",
                   "Een waarde van '380' als oriëntatie is ongeldig. De waarde voor de oriëntatie moet in het bereik [0,00, 360,00] liggen.")]
+        [TestCase("validConfigurationStepSizeOutOfRange.xml",
+                  "Een waarde van '5' als stapgrootte is ongeldig. De waarde voor de stapgrootte moet in het bereik [0,01, 2,00] liggen.")]
         public void Import_ValidConfigurationInvalidData_LogMessageAndContinueImport(string file, string expectedErrorMessage)
         {
             // Setup
Index: Riskeer/Revetment/test/Riskeer.Revetment.IO.Test/test-data/WaveConditionsCalculationConfigurationImporter/validConfigurationStepSizeOutOfRange.xml
===================================================================
diff -u
--- Riskeer/Revetment/test/Riskeer.Revetment.IO.Test/test-data/WaveConditionsCalculationConfigurationImporter/validConfigurationStepSizeOutOfRange.xml	(revision 0)
+++ Riskeer/Revetment/test/Riskeer.Revetment.IO.Test/test-data/WaveConditionsCalculationConfigurationImporter/validConfigurationStepSizeOutOfRange.xml	(revision e5ae21624afdf7f1608f245f7719f9fe216a1bf2)
@@ -0,0 +1,6 @@
+<?xml version="1.0" encoding="utf-8"?>
+<configuratie versie="2">
+  <berekening naam="Berekening 1">
+    <stapgrootte>5</stapgrootte>
+  </berekening>
+</configuratie>
Index: Riskeer/Revetment/test/Riskeer.Revetment.IO.Test/test-data/WaveConditionsCalculationConfigurationWriter/completeConfiguration.xml
===================================================================
diff -u -r3a50ce192fa494387b46e9e18bc87835d117ea1a -re5ae21624afdf7f1608f245f7719f9fe216a1bf2
--- Riskeer/Revetment/test/Riskeer.Revetment.IO.Test/test-data/WaveConditionsCalculationConfigurationWriter/completeConfiguration.xml	(.../completeConfiguration.xml)	(revision 3a50ce192fa494387b46e9e18bc87835d117ea1a)
+++ Riskeer/Revetment/test/Riskeer.Revetment.IO.Test/test-data/WaveConditionsCalculationConfigurationWriter/completeConfiguration.xml	(.../completeConfiguration.xml)	(revision e5ae21624afdf7f1608f245f7719f9fe216a1bf2)
@@ -7,7 +7,7 @@
     <ondergrensbekleding>0.5</ondergrensbekleding>
     <bovengrenswaterstanden>1.4</bovengrenswaterstanden>
     <ondergrenswaterstanden>0.6</ondergrenswaterstanden>
-    <stapgrootte>1.0</stapgrootte>
+    <stapgrootte>1</stapgrootte>
     <voorlandprofiel>profiel1</voorlandprofiel>
     <orientatie>67.1</orientatie>
     <golfreductie>